This invention relates to ultraviolet curing processes and more particularly to an improved process for obtaining coatings having improved adhesion to tin free steel.
The search for essentially solvent-free, non-polluting, low energy-utilizing coating application methods has led to the rapidly increasing use of ultraviolet curable coating systems. However, because of the inherently low temperatures utilized in curing ultraviolet compositions, the adhesion of the cured film to the desired substrate has been poor. In particular, ultraviolet curing coatings applied to tin free steel have exhibited tendencies to peel off the substrate and have been particularly subject to chemical attack between the substrate and the coating itself.
Thus, it is an object of this invention to prepare ultraviolet curable coatings compositions having improved adhesion to various substrata, in particular, tin free steel.
It is another object of this invention to prepare ultraviolet curable coating compositions which are resistant to chemical attack and which cure rapidly under normal ultraviolet curing conditions.